Bottom Activated Retractable Control Surface for an Unmanned Undersea Vehicle

This patent application discloses a bottom-activated retractable control device that includes a fin member having a front edge, a trailing edge opposite to the front edge, a bottom edge between the front edge and the trailing edge, and an arm portion extending from and coextensive with the leading edge and away from the bottom edge. The arm portion includes a pivot pin extending in a perpendicular direction from each side of the arm portion. A pivot housing having an aperture is provided for receiving the pivot pin of the arm portion, the housing enabling both a vertical pivot of the fin member upon contact of the fin with an object and axial rotation of the fin about the arm portion of the fin member. A well formed in the bottom surface of an underwater vehicle corresponds in depth to a fully retracted position of the fin member and in width to any rotated position of the fin member. A spring member is joined between the pivot housing and the pivot pin, the spring member normally biasing the fin member away from the vehicle, the fin member pivoting into as much as an entirety of the well in response to a force against the control fin. 8 figures